The mealybug Oracella acuta, native to the southeastern US, was accidentally introduced into slash pine plantations in Guangdong Province in China in 1988. A classical biological control program was initiated in 1995,...The mealybug Oracella acuta, native to the southeastern US, was accidentally introduced into slash pine plantations in Guangdong Province in China in 1988. A classical biological control program was initiated in 1995, and the parasitoids Allotropa oracellae, Acerophaus coccois, and Zarhopalus debarri were imported from the US. A total of 19 972 parasitized mealybugs were shipped to China from 1996-2004, from which 15 430 wasps emerged, 12 933 of which were the three target species. Efforts to establish a mass-rearing program for the parasitoids in China failed. Five field release sites were established, and 6 020 parasitoids were released. Only 118 individuals of the three imported species were collected during establishment checks, although several wasps were collected 1-2 years after the last parasitoid release. Over 2 000 Anagyrus dactylopii, a cosmopolitan parasitoid, emerged from the parasitized mealybugs collected, a majority from the Taishan area near the site of the original introduction ofO. acuta. To date the imported parasitoids have failed to establish, and natural enemies have not noticeably reduced mealybug populations.展开更多
For capital-breeding insects,all resources available for adult metabolic needs are accumulated during larval feeding.Therefore,body size at adult eclosion represents the total energetic capacity of the individual.For ...For capital-breeding insects,all resources available for adult metabolic needs are accumulated during larval feeding.Therefore,body size at adult eclosion represents the total energetic capacity of the individual.For female capital breeders,body size is strongly correlated with lifetime fecundity,while in males,body size,which correlates with fitness,is less understood.In capital-breeding species with wingless,flightless,or dispersal-limited females,flight potential for male Lepidoptera has important implications for mate-finding and may be correlated with body size.At low population densities,failure to mate has been identified as an important Allee effect and can drive the success or failure of invasive species at range edges and in species of conservation concern.Th capital-breeding European subspecies of Lymantria dispar(L.),was introduced to North America in 1869 and now ranges across much of eastern North America.In L.dispar,females are flightless and mate-finding is entirely performed by males.We quantified male L.dispar flight capacity and propensity relative to morphological and physiological characteristics using fixed-arm flight mills.A range of male body sizes was produced by varying the protein content of standard artificial diets while holding other dietary components constant.Wing length,a proxy for body size,relative thorax mass,and forewing aspect were all important predictors of total flight distance and maximum speed.These results have important implications for mate-finding and invasion dynamics in L.dispar and may apply broadly to other capital-breeding insects.展开更多
The polyphagous shot hole borer （PSHB）, Euwallacea sp., was first detected in 2003 in Los Angeles County, California, USA. Recently, this invasive species has become a major pest of many hardwood trees in urban and ...The polyphagous shot hole borer （PSHB）, Euwallacea sp., was first detected in 2003 in Los Angeles County, California, USA. Recently, this invasive species has become a major pest of many hardwood trees in urban and wildland forests throughout southern California. PSHB is nearly identical in morphology and life history to the tea shot hole borer （TSHB）, Euwallaceafornicatus, an invasive pest of hardwoods in Florida, USA and many other parts of the world. However, molecular studies have suggested that the taxa are different species. We conducted morphometric and chemical analyses of the pheno- types of Euwallacea sp. collected in southern California （Los Angeles County） and E. fornicatus collected in Florida （Miami-Dade County）. Our analyses indicated that PSHB has 3 larval instars. The third larval instar was separated from the first 2 instars by head capsule width with 0 probability of misclassification. The body length, head width, and pronotal width of PSHB adult males were significantly less than those of females. Head width and pronotal width of female PSHB were significantly less than those of female TSHB. In contrast, body length, and ratio of body length to pronotal width of female PSHB were significantly greater than those of female TSHB. However, females of these 2 species could not be separated completely by these 4 measurements because of the overlapping ranges. Cuticular hydrocarbons detected in both species were exclusively alkanes （i.e., n-alkanes, monomethylalkanes, dimethylalkanes, and trimethylalkanes）. Cuticular hydro- carbon profiles of PSHB males and females were similar, but they both differed from that of TSHB females. Cuticular hydrocarbons of PSHB were predominantly internally branched dimethylalkanes with backbones of 31 and 33 carbons, whereas cuticular hydro- carbons of TSHB females were dominated by internally branched monomethylalkanes and dimethylalkanes with backbones of 28 and 29 carbons. Multiple compounds within these classes appear to be diagnostic for PSHB and TSHB, respectively.展开更多
基金The authors thank Weyerhaeuser Company, Union Camp Company, Mississippi Department of Forestry, Texas For- est Service, and Bowater Inc. for the use of their seed orchards for parasitoid collections. Chris Crowe, Mark Dalusky, and Mike Cody （Univeristy of Georgia） assisted with the field work in the US, and Tian-song Fang and Jia-xiong Xu （Guangdong Forest Research Institute） and many workers at the TaiShan Seed Orchard helped with field releases and surveys in China. The USDA Forest Service provided funding for travel and field work, par- tial support was also provided by the National Science Foundation of China （30525009）. Alan Bullard （USDA FS）, Wayne Berisford （University of Georgia）, and Jian Wu （State Forestry Administration） also helped support the project. The authors also thank Bill Roltsch （CDFA） and Jim Hanula （USDA FS SRS） for their reviews of an earlier draft of this paper.
文摘The mealybug Oracella acuta, native to the southeastern US, was accidentally introduced into slash pine plantations in Guangdong Province in China in 1988. A classical biological control program was initiated in 1995, and the parasitoids Allotropa oracellae, Acerophaus coccois, and Zarhopalus debarri were imported from the US. A total of 19 972 parasitized mealybugs were shipped to China from 1996-2004, from which 15 430 wasps emerged, 12 933 of which were the three target species. Efforts to establish a mass-rearing program for the parasitoids in China failed. Five field release sites were established, and 6 020 parasitoids were released. Only 118 individuals of the three imported species were collected during establishment checks, although several wasps were collected 1-2 years after the last parasitoid release. Over 2 000 Anagyrus dactylopii, a cosmopolitan parasitoid, emerged from the parasitized mealybugs collected, a majority from the Taishan area near the site of the original introduction ofO. acuta. To date the imported parasitoids have failed to establish, and natural enemies have not noticeably reduced mealybug populations.
基金Funding was provided by Macrosystems Biology(Grant 1702701 to Kristine Grayson,Sal Agosta,and Dylan Parry)Gypsy Moth Slow-the-Spread Foundation,Inc(Grant 19-01-13 to DP).
文摘For capital-breeding insects,all resources available for adult metabolic needs are accumulated during larval feeding.Therefore,body size at adult eclosion represents the total energetic capacity of the individual.For female capital breeders,body size is strongly correlated with lifetime fecundity,while in males,body size,which correlates with fitness,is less understood.In capital-breeding species with wingless,flightless,or dispersal-limited females,flight potential for male Lepidoptera has important implications for mate-finding and may be correlated with body size.At low population densities,failure to mate has been identified as an important Allee effect and can drive the success or failure of invasive species at range edges and in species of conservation concern.Th capital-breeding European subspecies of Lymantria dispar(L.),was introduced to North America in 1869 and now ranges across much of eastern North America.In L.dispar,females are flightless and mate-finding is entirely performed by males.We quantified male L.dispar flight capacity and propensity relative to morphological and physiological characteristics using fixed-arm flight mills.A range of male body sizes was produced by varying the protein content of standard artificial diets while holding other dietary components constant.Wing length,a proxy for body size,relative thorax mass,and forewing aspect were all important predictors of total flight distance and maximum speed.These results have important implications for mate-finding and invasion dynamics in L.dispar and may apply broadly to other capital-breeding insects.
文摘The polyphagous shot hole borer （PSHB）, Euwallacea sp., was first detected in 2003 in Los Angeles County, California, USA. Recently, this invasive species has become a major pest of many hardwood trees in urban and wildland forests throughout southern California. PSHB is nearly identical in morphology and life history to the tea shot hole borer （TSHB）, Euwallaceafornicatus, an invasive pest of hardwoods in Florida, USA and many other parts of the world. However, molecular studies have suggested that the taxa are different species. We conducted morphometric and chemical analyses of the pheno- types of Euwallacea sp. collected in southern California （Los Angeles County） and E. fornicatus collected in Florida （Miami-Dade County）. Our analyses indicated that PSHB has 3 larval instars. The third larval instar was separated from the first 2 instars by head capsule width with 0 probability of misclassification. The body length, head width, and pronotal width of PSHB adult males were significantly less than those of females. Head width and pronotal width of female PSHB were significantly less than those of female TSHB. In contrast, body length, and ratio of body length to pronotal width of female PSHB were significantly greater than those of female TSHB. However, females of these 2 species could not be separated completely by these 4 measurements because of the overlapping ranges. Cuticular hydrocarbons detected in both species were exclusively alkanes （i.e., n-alkanes, monomethylalkanes, dimethylalkanes, and trimethylalkanes）. Cuticular hydro- carbon profiles of PSHB males and females were similar, but they both differed from that of TSHB females. Cuticular hydrocarbons of PSHB were predominantly internally branched dimethylalkanes with backbones of 31 and 33 carbons, whereas cuticular hydro- carbons of TSHB females were dominated by internally branched monomethylalkanes and dimethylalkanes with backbones of 28 and 29 carbons. Multiple compounds within these classes appear to be diagnostic for PSHB and TSHB, respectively.
